Lubricating compositions



LUBRICATIN G COMPOSITIONS Charles E. Francis, Martinez, Calif., assignor to Shell Development Company, Emeryville, Calih, a corporation of Delaware No Drawing. Application May 6, 1952, Serial No. 286,443

16 Claims. (Cl. 25251.5)

This invention relates to improved lubricating compositions particularly effective as turbine oils.

The essential requirements of a good lubricating turbine oil are that it be resistant to emulsification and oxidation and that it inhibit corrosion or rusting of metal parts exposed thereto. Lubricants which are normally regarded as effective corrosion and rust inhibiting compositions have been observed to be inefiective in this respect when used as turbine oils. The reason for the inability of such lubricating compositions to efiectively function as turbine oil lubricants appears to be due to their inability to resist emulsification in the presence of water.

It is an object of this invention to produce an improved rust and corrosion inhibited turbine oil. Still another object of this invention is to produce a turbine oil which is resistant to emulsification in the presence of Water. Another object is that it resists oxidation. Other objects of his invention will appear as the description proceeds.

It has now been discovered that excellent emulsion and oxidation resistant and corrosion inhibiting turbine oils can be prepared by addition (to a base oil) of minor amounts, but in controlled proportions, of: (a) an oilsoluble aliphatic polycarboxylic acid and/or an amide or a partial ester of said acid, (b) an oil-soluble phenolic compound or its thio or seleno analogues, and (c) an aromatic carboxylic acid.

(a) Oil-soluble aliphatic polycarboxylic acid and derivatives thereof The oil-soluble aliphatic polycarboxylic acids can be mono or polyalkyl or alkenyl substituted polycarboxylic acids, wherein the alkyl or alkenyl group or groups contain from 3 to 36 and preferably from 8 to 18 carbon atoms. Such acids include oil-soluble C6 to C36 and preferably C8 to C18 alkyl or alkenyl malonic, succinic, glutaric, adipic, pirnelic, sebacic, azelaic, tartaric, citric, maleic, citraconic acids, of which the preferred acids are C16 alkenyl succinic acid, C18 alkenyl succinic acid, C36 alkenyi succinic acid, Clo-C18 alkyl tartaric acid, Clo-C18 alkyl malonic acid. Partial or full amides and/or the partial esters of these acids can be used, and include alkyl succinic acid monoamide or alkenyl monooleyl succinate, alkyl monooctyl sebacate, alkyl monobutyl tartrate, monoisopropyl citrate, mono 2-ethy1hexyl citrate, ester of wax phenol and alkenyl succinic acid, ethyl decenyl succinate, decyl isobutenyl succinate, alkenyl succinic acid mono (-dicyclohexyl)amide, C16 succinic acid mono(2-ethylhexyl)amide, C18 alkenyl succinic acid monoamide; alkenyl thiosuccinic acid, alkenyl thio tartaric acid, 2-(l-thiotridecyl)succinic acid, 2-(1-thio-decyl)tartaric acid, 2- (l-thio-amyl)citric acid, etc., and mixtures thereof.

(b) The oil-soluble phenolic compound The oil-soluble phenolic compound can be oil-soluble alkyl phenols, naphthols or their thiol and the selenium analogues. The aromatic phenolic compounds can be alkylated by any known suitable means or they may be natural products such as phenols, cresols, etc., obtained aired rates Patent C 2,715,,id8 Patented Aug. 9, 1955 from petroleum hydrocarbons, coaltars and the like. If the phenolic material is to be alkylated, alkenes and their mixtures containing from 4 to 20 carbon atoms in the molecule can be used as the alkylating material. Mixtures of alkenes derived from paraflin waxes by cracking or from higher fatty alcohols by dehydration, are valuable and easily accessible starting materials. More than one alkyl group may be present in the phenol as in the case of compounds made by the dior tri-alkylation of phenols with alkenes or alkyl halides or alcohols or ethers or of compounds made by monoalkylation of, for example, a cresol, a xylenol, or carvacrol. Other nuclear substituents may be present provided they do not increase substantially the water solubility of the product. Thus halogen, alkoxy, alkylarnino, nitro groups may be present in the phenol. Moreover, dior polyhydric phenols such as catechol, resorcinol, pyrogallol and the dihydroxy naphthalenes may be alkylated to produce Water-insoluble and oil-soluble phenols useful for the purpose of this invention. Specific compounds which are represented by the above general formula and which can be used in compositions of this invention are: 2,4-dimethyl-6-tertiary butylphenol, 2,4,6-trimethylphenol, 2,4-dimethyl-6-tertiary octylphenol, 2,6-dibutyl-4-methylphenol, 2,4-dioctyl- 6-methylphenol, 2-ethyl-4-octylphenol, 1,4-dihydroxy-2- (2-octyl)benzene, 2,4-dimethyl-6-tertiary butyl naphthol, 2,4-dioctyl naphthol, 2,4-dimethyl-6-tertiary butyl thiophenol, 2,4-dimethyl-6-tertiary butyl selenophenol, 2- ethyl-4-octyl thiophenol, 2,4-dioctyl-6-methyl thionaphthol, 2,4-dimethyl-6-tertiary octyl tellurophenol, C14 alkylated cardanol, C14 alkylated thiocardanol, dodecyl phenol, bis-(beta-naphthylamino methyl)-p-tert-amylphenol, o-nitroso m-cresol, p-octyl aminophenol, dibutyl resorcinol, 2,6-ditertiary butyl-4-methylphenol, 2,4-ditertiary butyl-6-methylphenol, 2,4-di-sec-butyl-6-tertiary-butylphenol, 2,4-di-n-butyl-6-tertiary-octylphenol, 2,6-ditertiarybutyl-4-benzylphenol, 2,6-ditertiary-amyl-4methylphenol, 2,4-ditertiary-amyl-G-methylphenol, 2,4,6-tritertiary-butylphenol, 2,6-ditertiary-butyl-4-methylthiophenol, 2,4-ditertiary-butyl-6-methylthiophenol, 2,4-dimethyl-6-tertiarybutylthiophenol, 2,4-dimethyl-6-tertiary-octylthiophenol, 2,6-ditertiary-amyl-4-methylthiophenol, 2,4,6-tritertiaryamylthiophenol, 2,2-methylene bis(4-methyl-6-tertiary butylphenol), 2,2'-methylene bis(4,6-ditertiary-butylphenol), 2,2'-methylene bis(4,6-ditertiary-octylphenol), 2,2- methylene bis(4-methyl-6-tertiary-amylphenol), 2,2- methylene bis(4-methyl-6-tertiary-octylphenol), 2,2- methylene bis(4-methyl-o-tertiary-butylthiophenol), 2,2- methylene bis(4-octyl-6-tertiary-butylthiophenol), 2,2-

methylene bis(4,6-ditertiary-butylthiophenol), '2,2'-methylene. bis(4,6-ditertiary-amylthiophenol), 2,2-methylene bis (4-methyl-6-tertiary-amylthiophenol) 2,2-methylene bis (4-methyl-6-tertiary-octylthiophenol) (2-hydroxy-3- tertiary-butyl-S-methylphenyl)-furylmethane, (Z-hydroxy- S-tertiary-butylphenyl -furylmethane, l,1-bis(2-hydroxy 3-tertiary-butyl-S-methylphenyl) isobutane, bis(2-hydroxy 3 tertiary butyl 5 methylphenyl)phenylmethane, 2,2-bis(2-hydroxy-3-tertiary-butyl-5-methylphenyl)propane, 2,2-bis(Z-hydroxy-3-tertiary-butyl-5- methylphenyDbutane, and mixtures thereof.

(0) Aromatic acids Aromatic acids which can be used in combination with the above two classes of additives, in order to eiiect demulsification can be represented by the general formula:

wherein Ar is an aromatic nucleus; X may be a nonpolar or polar radical attached to the aryl nucleus; X may be a hydrocarbon radical containing if desired, a polar group; Z is a carboxylic acid group such as CYYH, wherein both Ys are selected independently from oxygen,

sulfur, selenium, and tellurium, said acid group being attached directly to the aryl nucleus or linked to it through X; m may be zero or an integer of from 1 to 3; 11 may be zero or one and may be an integer of l. or 2.

Representative acids are: benzoic, phthalic, toluic, xylic, phenyl fatty acids, e. g., phenyl acetic to phenyl stearic acids, cinnamic acid, salicylic acid, mandelic acid, phenyl glyoxylic acid, benzoyl propionic acid, phenyl laevulnic acid, phenyl alkyl succinic acid, benzyl alkyl succinic acid, phenyl alkyl glutaric acid, o-vinyl benzoic acid, phenyl angelic acid, naphthoic acid, naphthyl stearic acid, anthranilic acid, mercapto (phenyl, tolyl, xylyl, xenyl, naphthyl, anthracyl) fatty acids, e. g., phenyl mercapto acetic to phenyl mercapto stearic acid, ethyl mercapto phenyl acetic acid, alkyl mercapto benzene-4-carboxylic acid.

The base for additives of this invention can be an oleaginous material, i. c. any natural or synthetic material, having lubricating properties. Thus the base may be a hydrocarbon oil obtained from a parafiinic, naphthenic, Mid-continent or Coastal stock and/or mixtures thereof and preferably base stocks which have been highly refined. The viscosity of these oils may vary over a wide range such as from $0 SUS at 100 F. to 100 SUS at 210 F. Synthetic oils include olefin polymers, silicone fluids, organic phosphates, esters of polycarboxylic acid, e. g. di- 2-ethylhexyl sebacate, adipate and the like. Mixtures of synthetic and natural base oils also can be used.

The additive combination of this invention is used in amounts of about 1% or less and preferably in a total amount of less than 0.9%. The phenolic compound is present in the predominant amount of about 0.5%. The polycarboxylic acid (or derivative thereof) is generally used in amounts of from 0.01 to .2%, while the aromatic acid is present in the additive mixture in the least amount, generally in an amount of about 0.01% or less, based on the finished composition.

The general formula of compositions of this invention can be set forth as follows:

General Preferred Range Range Oil-soluble aliphatic polycarboxylic acid and Percent Percent derivatives thereof 0. 01-0. 2 0. 01-0. 05. Oil-soluble phenolic compound 0. 01-1. 0 0. 1-0. 8. Aromatic acid 0. 001-0. 01. 0. 001-0. 01. Base Oil Balance. Balance.

Preferred compositions of this invention are illustrated by the following examples:

Composition A: Per cent by weight Composition E: Per cent by weight Chi-C18 alkyl malonic acid 0.03 2,4-dioctyl-6-methyl phenol 0.6 Mandelic acid 0.003

Mineral oil Balance Composition F:

GIG-C18 alkyl tartaric acid 0.04 2,6-ditert-butyl-4-methyl phenol 0.6 Cinnamic acid 0.02

Mineral oil Balance Composition G:

C36 alkenyl succinic acid 0.03 2,2 methylene bis(4 methyl 6 tert-butyl phenol) 0.6 Benzoic acid 0.02 Mineral oil Balance Composition H:

Monoester of oleyl alcohol and C18 alkenyl succinic acid 0.03 2,6-ditert-butyl-4-methyl phenol 0.5 Toluic acid 0.01

Mineral oil Balance Composition 1:

C13 alkenyl succinic acid monoamide 0.04 2,4,6-tritert-amyl phenol 0.6 Benzoic acid 0.01 Mineral oil Balance I II III Composition :33,?3? Rust Test 2 igg i g ASTM Y (F. S. 320.1 D 665 50T) (ASTM VV-L-791) D-943-47T) Composition A Excellent Excellent... Excellent. Composition B-.. do

Composition Y b Poor. Composition Z a 1 Excellent-complete demulsification in less than 15-30 minutes in both distilled and synthetic sea water. Fairat least 1-3 ml. of emulsion remains around 30 minutes. Poor-at least 5-80 ml. of emulsion remains after 30 minutes. 2 Excellentno rust after 48 hours.

Fairsome rust noted after 48 hours. Poorrust noted in less than 24 hours. 3 Excellentover 1,000 hours. Fair-less than 600 hours. Poorless than 200 hours. 8 Composition X comprises mineral oil base having incorporated therein about 0.3% each of On; alkenyl succinic acid and 2,6 ditert-butyl- -methyl phenol.

b Composition Y comprises mineral oil base having incorporated therein about 0.3% Ci; alkenyl succinic acid.

Composition Z comprises mineral oil base having incorporated therein about 1% of 2,6-ditert-butyl-4-methyl phenol.

As can be noted from the above test results, compositions of this invention are excellent rust inhibitors and are resistant to emulsification.

Other additives can be added to compositions of this invention such as oiliness agents, extreme pressure agents, anticlogging agents and the like, in amounts of from 0.001% to 5% by weight.

In addition to being excellent turbine oils, compositions of this invention can be utilized as hydraulic oils, cutting fluids, drawing and rolling oils and the like.

i claim as my invention:

1. An improved lubricant consisting essentially of a major amount of a mineral lubricating oil and minor amounts, sufiicient to inhibit oxidation and corrosion of (a) an oil-soluble organic compound selected from the group consisting of oil-soluble hydrocarbyl-substituted aliphatic polycarboxylic acids, their monoesters and monoamides, (b) an oil-soluble phenolic compound, and a minor amount of about 0.01%, which amount is sufficient to effect complete demulsification, of (0) organic acidic compound selected from the group consisting of benzoic acid, salicylic acid, anthranilic acid, cinnamic acid and toluic acid.

2. An improved lubricant consisting essentially of a major amount of a mineral lubricating oil and minor amounts, suflicient to inhibit oxidation and corrosion of (a) an oil-soluble hydrocarbyl substituted aliphatic dicarboxylic acid, (b) an oil-soluble alkyl phenol, and a minor amount of about 0.01%, which amount is sufficient to effect complete demulsification, of (c) organic acidic compound selected from the group consisting of benzoic acid, salicylic acid, anthranilic acid, cinnamic acid and toluic acid.

3. An improved turbine oil consisting essentially of a major amount of a mineral lubricant oil and minor amounts, sufficient to inhibit oxidation and corrosion of (a) an oil-soluble alkenyl substituted aliphatic dicarboxylic acid, (b) an oil-soluble polyalkyl phenol, and a minor amount of about 0.01%, which amount is sufiicient to effect complete demulsification, of (c) organic acidic compound selected from the group consisting of benzoic acid, salicylic acid, anthranilic acid, cinnamic acid and toluic acid.

4. An improved turbine oil consisting essentially of a major amount of a mineral oil and minor amounts, suflicient to inhibit oxidation and corrosion of (a) an oil-soluble C18 alkenyl succinic acid, (b) an oil-soluble trialkyl phenol and a minor amount of about 0.01%, which amount is sufficient to effect complete demulsification, of (0) organic acidic compound selected from the group consisting of benzoic acid, salicyclic acid, anthranilic acid, cinnamic acid and toluic acid.

5. An improved turbine oil consisting essentially of a major amount of a mineral oil and minor amounts, sufficient to inhibit oxidation and corrosion of (a) an oil-soluble C18 alkenyl succinic acid, (b) an oil-soluble 2,6-ditert-butyl-4-methyl phenol, and a minor amount of about 0.01%, which amount is sufficient to effect complete demulsification, of (c) a benzoic acid.

6. An improved turbine oil consisting essentially of a major amount of a mineral oil and minor amounts, sufficient to inhibit oxidation and corrosion of (a) an oil-soluble C13 alkenyl succinic acid, (b) an oil-soluble 2,6-ditert-butyl-4-methyl phenol, and a minor amount of about 0.01%, which amount is suflicient to effect complete demulsification, of (c) a cinnamic acid.

7. An improved turbine oil consisting essentially of a major amount of a mineral oil and minor amounts, suflicient to inhibit oxidation and corrosion of (a) an oil-soluble C18 alkenyl succinic acid, (b) an oil-soluble 2,6-ditert-butyl-4-methyl phenol, and a minor amount of about 0.01%, which amount is sufficient to effect complete demulsification, of (c) anthranilic acid.

8. An improved turbine oil consisting essentially of a major amount of a mineral oil and minor amounts. suificient to inhibit oxidation and corrosion of (a) an oilsoluble C18 alkenyl succinic acid monoamide, (b) an oil-soluble trialkyl phenol, and a minor amount of about 0.01%, which amount is suflicient to effect complete demulsification, of (c) an aromatic monocarboxylic acid.

9. An improved turbine oil consisting essentially cf a major amount of a mineral oil and minor amounts, sufiicient to inhibit oxidation and corrosion of (a) an oil-soluble C18 alkenyl succinic acid, (b) an oil-soluble 2,2methylene bis(4-methyl-6-tert-butyl phenol), and a minor amount of about 0.01%, which amount is sufficient to effect complete demulsification, of (c) benzoic acid.

10. A turbine oil capable of resisting emulsification having the following formula:

Per cent C18 alkenyl succinic acid 0.025

2,6-ditert-butyl-4-methyl phenol 0.5

Benzoic acid 0.003

Mineral oil Balance 11. A turbine oil capable of resisting emulsification having the following formula:

Benzoic acid 0.0010.01

Mineral oil Balance 14. A turbine oil capable of resisting emulsification having the following formula:

Per cent C18 alkenyl succinic acid 0.1-0.8

2,6-ditert-butyl-4-methyl phenol 0.01-005 Cinnamic acid 0.00l0.01 Mineral oil Balance 15. A turbine oil capable of resisting emulsification having the following formula:

Per cent C18 alkenyl succinic acid 0.1-0.8 2,6-ditert-butyl-4-methyl phenol 0.010.05

Anthranilic acid 0.00l0.01 Mineral oil Balance 16. A turbine oil capable of resisting emulsification and oxidation having the following formula:

Per cent Oil-soluble aliphatic polycarboxylic acid 0.010.2 Oil-soluble phenolic compound 0.01-1

An aromatic monocarboxylic acid selected from the group consisting of benzoic acid,

salicyclic acid, anthranilic acid, cinnamic acid and toluic acid 0.000l0.01 Mineral oil Balance References Cited in the file of this patent UNITED STATES PATENTS 2,249,333 Smith July 15, 1941 2,334,158 Fuchs Nov. 9, 1943 2,340,920 Archibald Feb. 8, 1944 2,434,978 Zisman Jan. 27, 1948 2,440,530 Yates Apr. 27, 1948 2,442,672 Fuchs June 1, 1948 2,459,717 Perry Jan. 18, 1949 OTHER REFERENCES Performance of Lubricating Oils, by Zuidema Reinhold Pub. Co., New York, 1952, page 130. (Copy in Scientific Library.) 

1. AN IMPROVED LUBRICANT CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF A MINERAL LUBRICATING OIL AND MINOR AMOUNTS, SUFFICIENT TO INHIBIT OXIDATION AND CORROSION OF (A) AN OIL-SOLUBLE ORGANIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF OIL-SOLUBLE HYDROCARBYL-SUBSTITUTED ALIPHATIC POLYCARBOXYLIC ACIDS, THEIR MONOESTERS AND MONOAMIDES, (B) AN OIL-SOLUBLE PHENOLIC COMPOUND, AND A MINOR AMOUNT OF ABOUT 0.01%, WHICH AMOUNT IS SUFFICIENT TO EFFECT COMPLETE DEMULSIFICATION, OF (C) ORGANIC ACIDIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF BENZOIC ACID, SALICYLIC ACID, ANTHRANILIC ACID, CINNAMIC ACID AND TOLUIC ACID. 